The 'Imagines' of Philostratus the Elder and his grandson Philostratus the Younger, is the only book surviving from antiquity that deals solely with the appreciation of painting. The thesis describes and analyses the ways in which the 'Imagines' has been rediscovered, translated, read and interpreted by humanists, artists and their patrons, from the time of the first printed edition in 1503 to the beginning of the seventeenth century when its popularity with artists diminished.